From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Gallatin Subject: Re: [PATCH net-next] gro: Handle inline VLAN tags Date: Mon, 26 Nov 2012 10:04:44 -0500 Message-ID: <50B3850C.4070902@myri.com> References: <1353111414.10798.64.camel@edumazet-glaptop> <1353112324.2743.81.camel@bwh-desktop.uk.solarflarecom.com> <1353114559.10798.66.camel@edumazet-glaptop> <20121119.191002.1995098917961576324.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: eric.dumazet@gmail.com, bhutchings@solarflare.com, netdev@vger.kernel.org, linux-net-drivers@solarflare.com, herbert@gondor.hengli.com.au To: David Miller Return-path: Received: from mail-gg0-f174.google.com ([209.85.161.174]:36613 "EHLO mail-gg0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753249Ab2KZPEr (ORCPT ); Mon, 26 Nov 2012 10:04:47 -0500 Received: by mail-gg0-f174.google.com with SMTP id k2so1966122ggd.19 for ; Mon, 26 Nov 2012 07:04:47 -0800 (PST) In-Reply-To: <20121119.191002.1995098917961576324.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On 11/19/12 19:10, David Miller wrote: > From: Eric Dumazet > Date: Fri, 16 Nov 2012 17:09:19 -0800 > >> On Sat, 2012-11-17 at 00:32 +0000, Ben Hutchings wrote: >>> On Fri, 2012-11-16 at 16:16 -0800, Eric Dumazet wrote: >>>> On Sat, 2012-11-17 at 00:00 +0000, Ben Hutchings wrote: >>>> >>>>> I'm not sure what you mean by this. Is your point that the >>>>> copy-on-write is never needed? It is still possible for pskb_may_pull() >>>>> to fail. >>>>> >>>> >>>> A packet sniffer should have a copy of bad frames, even if dropped later >>>> in our stacks. >>>> >>>> GRO layer is not allowed to drop a frame, even if not 'correct'. >>> >>> What do you think the accelerated hardware does with frames that have a >>> truncated VLAN tag? >> >> The hardware should send us the frame, exactly like when RX checksum is >> wrong. > > I agree with Eric, and therefore will not apply this patch. > David, How do you feel about the patchset I posted on 11/14/2012 ([PATCH net-next 0/3] myri10ge: LRO to GRO conversion, http://marc.info/?l=linux-netdev&m=135289838223920&w=2) which moves myri10ge from LRO to GRO? Specifically, if doing vlan decap in GRO is not OK, then how about doing it in the driver? BTW, if I have bungled something it the myri10ge patchset submission, I do apologize. I don't frequently submit patches, and it is likely I screwed up some convention.. Thanks, Drew